<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>文本格式化</title>
</head>
<body>
<b>文本加粗</b><br/>
<strong>加重语气</strong><br/>
<big>大号字</big><br/>
<em>着重语气</em><br/>
<i>斜体字</i><br/>
<small>定义小号字</small><br/>
This text contains
<sub>下标</sub><br/>
This text contains<sup>上标</sup>
</body>
</html>